---
type: threshold
id: methyl-ethyl-ketone-mek-2-butanone-ethyl-methyl-ketone
asset: workplace-exposure-limits
title: "Methyl ethyl ketone; MEK; 2-butanone; ethyl methyl ketone — US workplace chemical exposure limits: federal OSHA vs Cal/OSHA, side by side"
sources:
  - https://www.dir.ca.gov/title8/5155.html
source_quote: "78933 | | Methyl ethyl ketone; MEK; 2-butanone; ethyl methyl ketone | 200 | 590 | | 300 | 885"
generated: true
harvested: 2026-08-05
stale_after: 2027-08-05
substance: "Methyl ethyl ketone; MEK; 2-butanone; ethyl methyl ketone"
pel_ppm: "200"
pel_mgm3: "590"
stel_ppm: "300"
stel_mgm3: "885"
verified: true
---
**Substance:** Methyl ethyl ketone; MEK; 2-butanone; ethyl methyl ketone

**PEL (ppm):** 200

**PEL (mg/m³):** 590

**STEL (ppm):** 300

**STEL (mg/m³):** 885

> 78933 | | Methyl ethyl ketone; MEK; 2-butanone; ethyl methyl ketone | 200 | 590 | | 300 | 885

Source: <https://www.dir.ca.gov/title8/5155.html>